Most vehicle fuel tanks include a filler neck extending from the tank to allow a user to refill the tank with fuel. Some type of cap or cover is placed over the filler neck in order to seal the fuel tank from the atmosphere. Fuel tanks should be tightly capped to avoid the dangers of igniting the gasoline, to prevent environmental harm due to the escape of gasoline vapors and to reduce the intrusion of contaminates into the fuel tank.
The most common type of cover is a gas cap. Conventional gas cap assemblies are typically threaded onto the filler neck and include some type of locking handle. Each time the fuel tank is replenished, the gas cap must be unscrewed at the start of the refueling operation and then screwed back into position at the end of the refueling. Over time the interior ratcheting mechanism of the gas cap may wear out such that the gas cap may not be adequately secured to the filler neck or may be over-tightened. In the situation of the gas cap being over-tightened, the user may have great difficulty in subsequently removing the gas cap. In addition, the twisting removal of the gas caps creates a consistent inconvenience for the user, especially in inclement weather.
The prior art has also contemplated the use of a pivotal cover moveable between open and closed positions to open and close the filler neck. Examples of such pivotal covers for fuel tanks are shown in U.S. Pat. Nos. 5,327,946 and 5,503,199. An advantage of these designs is that the user does not have to remove the gas cap to fill the fuel tank. These prior art pivotal gas caps, however, require a separate locking device which must be independently actuated to facilitate the opening of the cover. Due to the confined spaces in which the pivotal cover is associated and the relatively small size of the locking device, the separate actuation of this device can be cumbersome and difficult to accomplish.
Accordingly, it is desirable to develop a gas cap cover which pivots between open and closed positions to open and close a filler neck of a fuel tank without actuating a separate locking device.